Construction elements for contact banks in automatic telephone systems



AGENT May 22, W56 G. M. P. A. BEERS 297479144 CONSTRUCTION ELEMENTS FOR CONTACT BANKS IN AUTO IC TELE F d Jan ONE SYSTEMS 1955 INVENTOR G ERARDUS M ARCUS PETRUS ADRIANUS EEERS BY K United States Patent CONSTRUCTION ELEMENTS FOR CONTACT Bfilcl lls IN AUTOMATIC TELEPHONE SYS- T Gerardus Marcus Petrus Adrianus Beers, Hilversum, Netherlands, assignor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application January 2, 1953, Serial No. 329,381

Claims priority, application Netherlands January 10, 1952 4 Claims. (Cl. 317-112) This invention relates to construction elements for contact banks used in automatic telephone systems or the like, which elements comprise a plate of insulating material accommodating a number of parallel contact members laterally projecting from the plate at least at one side and said plate further comprising a number of parallel multiplying wires which extend parallel to the plane of the plate and at right angles to the contact members. Such construction elements permit a contact band to be built in a simple manner by stacking a number of said elements such that their fiat faces engage one another. The contact members laterally projecting from the plates thus form rows of fixed contacts which, for example by means of a selector switch, are wiped by brushes moving along said rows of contact. In known constructions the multiplying wires extend through a number of construction elements, thus connecting said elements like the beads of a string. Such linked construction elements permit a number of contact banks with multipled contacts to be built simultaneously.

The present invention has for its object a simple and cheap construction of an element referred to in the preamble, which is particularly adapted to mass-production. In accordance with the invention, the contact members consist of metal strips extending at right angles to the plane of the plate and being held in the plate since the insulating material at one side of the strip is connected through recesses therein to the material at the other side of the strip. An edge of said strips, which extends in a longitudinal direction, coincides with a fiat limiting surface of the plate, the central portion of the opposite edge of the strips freely engaging a recess provided in the opposite fiat limiting surface of the plate. Said recess is divided into a number of grooves by ribs extending between the contact members in a direction parallel thereto, each groove accommodating the said free edge of a contact member, and the multiplying wires resting on the ribs. The multiplying wires are preferably supported in position since they extend over the tops of the ribs and rest in a recess in the top of each rib, a multipled wire being electrically connected to a contact member by providing the former at the crossing of both members with a band engaging the groove in question and the tip of which is secured to the contact member.

In order that the invention may be readily carried into effect it will now be described with reference to the drawing representing one example of the construction element according to the invention, and in which:

Fig. 1 is a fiat elevation of the construction element;

Fig. 2 is a section on the line II-II;

Fig. 3 is a cross-section on the line Ill-III in Fig. 1; and

Fig. 4 is a perspective view of the relative position of a contact member and several multiplying wires of the construction element shown in the other figures.

The construction element as represented comprises a plate of synthetic material, for example, polystyrene, moulded or sprayed around eight parallel contact strips 2,747,144 Patented May 22, 1956 11. Although the contact strips 11 extend with their planes at right angles to the plane of plate 10 and the width of the contact strips substantially corresponds to the thickness of the plate, a unitary assembly is obtained since the material of the plate at one side of the contact strips is connected through recesses 12, 13 and 14 in said strips to the material at the other side. The contact strips 11 project from the plate 10 at both sides. The parts 15 of the contact members projecting at one side, are provided with an aperture 16 wherein any junction wires can be soldered or otherwise secured. When assembling a number of said plates by stacking them to form a contact bank, the other ends of the contact members constitute fixed contacts wiped by movable brushes. The lower edge of the contact members coincides with the bottom surface of plate 10. The upper surface of the plate is furnished at its center with a recess 17 freely engaged by the upper edges of the contact members. The recess 17 is divided into a number of parallel grooves 19, in each of which a contact member is accessible, by a number of ribs 18 parallel to the contact members, the top of said ribs being a little below the plate. The grooves 20 in the upper surface of the plate accommodate a number, at this instance eight, of parallel multiplying wires 21, each of which is supported in position by an incision 22 in the top of the ribs 18 (Fig. 4). The multiplying wires 21 extend at right angles of the plane of the contact strips 11. The wires 21 are further held by distorting the grooves 20, after receiving the wires, while heating. Each multiplying wire is electrically connected to one of the contact members, said connection being established by providing a multiplying wire, where it crosses a contact strip, with a bend 23 whose tip rests in an incision 24 provided in the free edge of the contact member and is held therein by distorting the edge of the contact member beside the incision. The multiplying wires may pass through a number of construction elements so that a number of plates like plate 10 are situated in spaced relationship on the multiplying wires 21. By stacking a number of elements in accordance with the represented construction element a contact bank is obtained wherein the ends, pointing to the left in Fig. 1, of the fixed contact members form rows of fixed contacts in a direction at right angles to the plane of the construction elements, said contacts being wiped, for example, by brushes of a brush-carriage movable along the bank.

While we have thus described our invention with specific examples and embodiments thereof, other modifications will be readily apparent to those skilled in the art without departing from the spirit and the scope of the invention as defined in the appended claims.

What I claim is:

1. A construction element for a contact bank in an automatic telephone system, said construction element comprising a fiat insulating plate having parallel ribs raised thereon to form a plurality of parallel grooves, each of said ribs having spaced transverse recesses therein, a plurality of parallel fiat contact strips having openings therein, said strips being embedded in said plate with the material thereof extending through said openings, said strips projecting from at least one edge of said plate, said strips projecting with part of one edge into said grooves, the other edge of each of said strips being flush with the lower surface of said plate, and a plurality of parallel multiplying wires extending through the transverse recesses of said ribs perpendicularly with respect to said strips, each of said wires being connected to at least one of said strips.

2. A construction element for a contact bank in an automatic telephone system, said construction element comprising a flat insulating plate having parallel ribs raised thereon to form a plurality of parallel grooves,

each of said ribs having spaced transverse recesses there in, a plurality of parallel flat metallic contact strips having openings therein, said strips being embedded in said plate with the material thereof extending through said openings, said strips projecting from at least one edge of said plate, one edge of each of said strips projecting into one of said grooves, the other edge of each of said strips being flush with the lower surface of said plate, and a plurality of parallel multiplying wires extending through the transverse recesses of said ribs perpendicularly with respect to said strips, each of said wires being connected to a least one of said strips.

3. A construction element, as set forth in claim 2, wherein said multiplying wires rest in recesses provided in the upper part of said ribs and wherein each of said multiplying wires is electrically connected to a predetermined contact strip by providing each of said wires with a bend at the point where the wire crosses said predetermined strip, said bend pointing to said predetermined strip and the tip of said bend connected to said predetermined strip.

4. A construction element, as set forth in claim 3, wherein each of said contact strip edges facing said multiplying wires is provided with incisions for receiving the bends of said multiplying wires and at least part of the material of said strips adjacent the surfaces defining said incisions being crimped at least partially around the tip of each of said bends for retaining the wires in said incisions.

References Cited in the tile of this patent UNITED STATES PATENTS 

